A friend of a man arrested on suspicion of murder in connection with a dismembered body found in San Francisco said Sunday that police got the wrong person.

Mark Andrus was taken into custody Friday at the apartment of Mark Keever after police received a tip on his whereabouts. He had been considered a person of interest since Wednesday, when a suitcase stuffed with human remains was found in the South of Market area. More body parts were found in a trash can nearby.

Police said security camera footage showed Andrus in the area where the dismembered body was dumped before a passerby discovered the suitcase.

However, Keever insisted on Sunday that Andrus was in the wrong place at the wrong time.

"It's wrong. It's not him," Keever told the San Francisco Chronicle.

"Because he happened to be walking by, looking like a transient, they arrested him," Keever said. "I'm not trying to cover for him, but it's the truth."

A call to a police spokesperson has not been return.

When Andrus' arrest was announced, Officer Grace Gatpandan, a police spokeswoman, wouldn't say how investigators linked Andrus to the body but said they were aided by the surveillance footage and witness statements.

Police have until Tuesday to present the case to prosecutors, who will decide whether to file formal charges.

San Francisco Public Defender Jeff Adachi told the Chronicle he visited Andrus at the county jail and that Andrus "already indicated to me he wants our office to represent him." If prosecutors decide to file charges, Adachi said Andrus will plead not guilty because his office hasn't been able to investigate the case.