Handmade card illustrated with multi-colored crayons on light purple paper. The front features a child's illustration of an animal, perhaps a horse, with its mouth open wide in the shape of the letter C. The back features a blob outlined in brown crayon and other undecipherable imagery.

Printed signs in blue and green ink on paper. The signs urge the reader to "Show solidarity" and "stand up for our common values, today tomorrow and always." An illustration of three stylized people raising their hands appears in the upper center, surrounded by the words: "Kindness, Respect, Courage."

Card from a student at West Allegheny Middle School in Imperial, Pa. The front features a hand-colored illustration of a flower with geometric motifs. The back contains a handwritten note, as well as a partial stock signature: "From your friends at West Allegheny Middle School."

Square card with white and yellow text against blue background. Card reads, "Mitzvah4Pittsburgh. Some spread darkness. We spread light. Choose a good deed. Choose a Mitzvah. Add light to the world," followed by four options and a place for respondents to list their name and email address. Some names and email addresses have been redacted for privacy.

Business card from Reverend John Shaver of San Dieguito Methodist Church in Encinitas, Ca.

Folded card on red paper. Due to exposure to the elements at the Wilkins memorial, the message on this card is no longer visible.

Card from a student at West Allegheny Middle School in Imperial, Pa. The front features a hand-colored illustration of the words: "Be Strong" and other floral and geometric motifs. The back contains a handwritten note, as well as the stock signature: "From your friends at West Allegheny Middle School."

Collage with a hand drawn tree in the center; leaves comprised of multicolored tissue paper. Tree trunk is shaded with purple crayon and outlined in black ink; handwritten messages in fuchsia ink and pencil on either side.

Post-it note with handwritten message in black marker. The message reads: "With you in strength and heartbreak and love that remembers all that you are."

Card from a congregant at the Holy Angels Parish. The front cover contains a stock illustration of seven children holding hands around a table with a large goblet and loaf of braided bread, and seven doves. The illustration is labeled: "We are people of God's peace." The inside reads: "To Tree of Life members and to Jewish everywhere. Adam and Eve let sin in the world, but God gave us another option, Jesus. But through terrorism nothing ever, will drive us apart from being a religious nation. We are one people if they are any differences we should talk them out.

Card from a congregant at the Holy Angels Parish. The front cover contains a stock illustration of seven children holding hands around a table with a large goblet and loaf of braided bread, and seven doves. The illustration is labeled: "We are people of God's peace." The inside reads: "We are praying for you." The card has been embellished with multi-colored horizontal lines.

Note from a member of The Church at Severn Run in Severn, Maryland. The note is enclosed in an envelope with church letterhead, reading: "The Church at Severn Run: Love Well, Live Jesus, Believe Big!" The note inside affirms the sender's belief that we are all God's children. The church's contact information is included on the back of the envelope.

Blank pink envelope with tape affixed on the reverse. Staining and fading due to exposure to the elements at the Wilkins memorial.

Letter from a member of the Point Loma Community Presbyterian Church in San Diego, California. The front cover of this card features a heart with the words "God is love." The inside reads: "May you find God's comfort in knowing we are with you in spirit- May the spirit of God stir in the souls of all on our earth to stop the violence against God's people. We want peace on earth and it starts with us knowing our God of peace and love. God bless you and your whole community of believers. Pt Loma Community Pres. Church Loves you all."

Card from a student at West Allegheny Middle School in Imperial, Pa. The front features a hand-colored illustration of the words: "Keep going" and a pattern with flowers, leaves, arrows, and shooting stars. The back contains a handwritten note, as well as the stock signature: "From your friends at West Allegheny Middle School."

Letter from a member of the Point Loma Community Presbyterian Church in San Diego, California. The letter is dated Nov. 4, '18 and reads: "We are so sorry to learn of the horrible tragedy that has befallen your church. Please know that we at Point Loma Pres. in San Diego are with you in prayer always and that God will always make things right in His own time and way. Stay strong in His word and trust Him to heal your hearts. In this we pray and support you from afar. Eric [last name redacted] PLPC."

Plain white poster board, cut crooked, with two strokes of red marker on the front. Price tag and additional stains on back. Extensive staining due to exposure to the elements at the Wilkins memorial.

Large square card from a student at Fountain Valley School in Colorado Springs, Co. Card features several messages on paper heart cut-outs. Message on upper left heart: "Dear members of Tree of Life Synagogue, I'm from China. I heard about the tragic news that happened on October 27th. I'm sorry for your loss..." Message on upper right heart reads: "I'm Christian, and I'm with you. Wish you all the BEST... I stand with you.

Post-it note with handwritten message in blue and red marker. The message reads: "Hate can't drown out hate. Only love can do that [heart]. By, Brandon."