Jordan Watson murder: Latest updates as police investigate 'savage' killing of 14-year-old boy
A vigil for Jordan has been organised to take place on Saturday evening.
Friends and local residents have suggested gathering at nearby Hammond's Pond to release lanterns and share memories.
Scott Pearson wrote on the page: "RIP Jordan. I remember Jordan from when I volunteered at the local youth project he attended occasionally.
"Always smiling and chatty and a respectful young man.
"The whole country is in total shock and saddened with this horrible situation.
"May you rest in peace Jordan, and when we all look to the sky at night I'm sure your star will be the brightest one in the sky. Sleep tight little man."
The suspect is known to Jordan and the murder weapon has not yet been found, police said.
DS Slattery told the press conference which ended a short time ago: "Extensive searches have taken place in the area of the cemetery and the surrounding parts of Carlisle.
"At 10.39am this morning a 18-year-old man from Carlisle was arrested on suspicion of Jordan's murder.
"However this is one line of inquiry. The investigation is ongoing and we are keeping an open mind about the motive and why indeed this crime took place.
"We would like to hear from anybody who has any information that can assist the investigation in any way. In particular, anybody who saw or heard anything unusual in the area of the cemetery or anybody who saw Jordan on the 15th of June."
Jordan who was 5ft, of slim build and with brown hair, was last seen wearing a blue and grey hoodie, black Adidas t-shirt, grey tracksuit bottoms and grey Nike trainers.